Cooling system for dry type transformers



1 Sept. 14, 1965 s. B. HEBERLIG 3,205,811

COOLING SYSTEM FOR DRY TYPE TRANSFORMERS Filed April 25, 1965 2 Sheets-Sheet 1 BY $nea4e/Me, @5515 627635705? p 1965 SB. HEBERLIG 3,205,811

COOLING SYSTEMFOR DRY TYPE TRANSFORMERS Filed April 25, 1965 2 Sheets-Sheet 2 United States Patent 3,205,811 COOLING SYSTEM FOR DRY TYPE TRANSFORMERS Sylvester B. Heberlig, Glenrlore, N..I., assignor t0 I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Apr. 25, 1963, Ser. No. 275,568 4 Claims. (Cl. 98-116) My invention relates to a novel cooling system for housings which contain electrical equipment, or the like, and more specifically relates to a novel cooling system for dry-type transformers.

Dry-type transformers are will known to the art and are usually contained within a housing or cubicle which is provided with some type of cooling system. The cooling system will normally be selectively operated either by natural convection or forced air cooling where increased capacity is required. Thus, outlet openings are provided in the transformer housing at the top of the housing, while air inlet openings are provided at the bottom of the housing. Moreover, forced cooling fans are usually placed adjacent to some of these bottom openings. Because of this, and when fan operation is required, there will be a loss of air through the adjacent bottom openings to result in ineflicient transfer of air from the bottom to the top of the housing.

The principle of the present invention is to provide a novel shutter for the air inlet openings which is nor mally open when the system operates on natural convection cooling, but is closed responsive to an increase in pressure created by fan operation. Thus, the shutter can be formed of a pivotally mounted vane which has a weight or other biasing means just sufficient to hold the shutter in an open position to permit introduction of air through the inlet openings during convection cooling. When, however, a forced cooling fan is turned on, the pressure within the housing increases to move the shutter closed against the force of its biasing means whereby air flow occurs directly from the fan to the various outlet openings in the housing and is not diverted through open inlet ports.

Accordingly, a primary object of this invention is to provide a novel cooling system for electrical equipmentcontaining housings.

Another object of this invention is to provide a novel shutter for the inlet air ducts of the housing which can be cooled by either natural convection or forced cooling.

A further object of this invention is to provide a novel shutter for the air inlet openings of a housing which can be cooled by either natural convection or forced cooling wherein the introduction of forced cooling causes the shutters to close inlet air ducts.

These and other objects of my novel invention will become apparent from the following description when taken in connection with the drawings, in which:

FIGURE 1 illustrates a side plan view of a housing for a dry-type transformer with a portion of the housing wall broken away.

FIGURE 2 is a top plan view of the housing of FIG- URE 1 with the upper housing cover removed.

FIGURE 3 is a top plan view of the mounting plate which carries the shutters and fan in the housing of FIG- URES 1 and 2.

FIGURE 4 is an enlarged view of one of the shutters of FIGURES 1 and 2.

FIGURE 5 is a detail view which illustrates the manner in which the shutter is pivotally mounted.

FIGURE 6 is a side plan view of FIGURE 4.

Referring first to FIGURES 1 and 2, I have illustrated therein a dry-type transformer 10 which has a magnetic core 11 and windings 12 formed in the usual manner.

Patented Sept. 14, 1965 The magnetic core is supported on an appropriate base 13 at the bottom of a housing 14 which completely encloses the transformer 10. That is to say the enclosure 14 has four side walls 15, 16, 17 and 18, as shown in FIGURE 2, and a top wall 19, as shown in FIGURE 1.

Two mounting plates and 31 are then carried immediately above the floor of the housing, and have openings therein such as the openings 32, 33 and 34 of FIG- URE 3 for the case of plate 30, wherein these openings communicate with areas external of housing 14 and serve as inlet air openings for the housing.

Appropriate louvers, or other appropriate openings such as the openings 35, schematically illustrated in FIGURE 1, are then provided in the upper portions of housing 14 to serve as air outlet openings. Thus, a path for air circulation is provided from the bottom of housing 14 to the top of housing 14 for cooling of the dry-type transformer 10.

In accordance with the invention, the openings 32 and 34 are controlled by shutters 36 and 37, as seen in FIGURE 2, while the opening 33 receives a fan or suitable air impelling means 40. In a similar manner, the plate 31 carries shutters 38 and 39 and a fan 41. As shown in FIGURE 2, the fans 40 and 41 may be electrically interconnected for simultaneous operation.

The manner in which the individual shutters 36 through 39 may be constructed is shown in FIGURES 4 through 6 for the case of shutter 36. Thus, as shown in FIGURE 4, a pair of block assemblies 42 and 43 are secured to plate 30 by appropriate fastening means extending through openings 44 and 45 in blocks 42 and 43 repectively. Each of blocks 42 and 43 have openings therein which receive appropriate bearing tubes such as the tube 46 of FIGURE 5 which could be of an appro priate self-lubricating material such as Teflon.

Thus, the tubes of mounting blocks 42 and 43 receive the ends of a rod 47 which is directly and rigidly secured to shutter 36 by means of appropriate mounting brackets 48 and 49. The upper portion of shutter 36 then carries an extending member 50 which overlaps with the edge of its opening 32 to prevent the upper portion of the shutter from moving below plate 30.

A balancing weight such as weight 52 is then secured to the bottom of shutter 36 by means of a securing screw 53 which passes through a slotted opening 54 in shutter plate 36 which permits the balancing weight 52 to be adjustably located at different radial positions of plate 36, thereby to adjust the opening biasing force on the shutter to zero. The weight 52 then has a screw 55 added to and extending into a threaded opening in weight 52, as illustrated.

The screw 55 is of a predetermined weight, which when inserted in weight 52, will provide the required opening biasing force on the shutter 36. Screw 55 also limits the travel of the shutter in the open position similar to the action of member 50 in the closed position.

In operation, and assuming that fans 40 and 41 are inoperative, the fan shutters will be in an open position, as illustrated in FIGURE 1 for shutters 36 and 38. Thus, the screw 55 is of sufiicient weight to cause plate 36 to rotate about the axis of rod 47 to the position illustrated in FIGURE 1. Under this condition, the inlet openings such as openings 32 and 34, as well as corresponding openings in plate 31, permit natural convection flow of air from the bottom of housing 14 upwardly past transformer 10 and through the outlet openings in the top of the housing. If it is now necessary to provide additional cooling, the fans 40 and 41 are turned on to provide forced cooling of transformer 10.

In the past, as noted above, the efiiciency of these fans was adversely affected since a considerable amount of air could escape through the open air inlet openings such as openings 32 and 34 in plate 30.

In accordance with the present invention, however, and since the surface of the shutters above the level of rod 47 in FIGURE 4 is greater than the surface below the axis of rod 47, a net force is applied to each of the shutters which is in a direction to move the shutters to a closed position with respect to their respective openings. Thus, when the fans are turned on, each of the shutters which were previously in an open position, will now rotate until their respective stops, such as stop 50 of shutter 36, engage their mounting plate 30 or 31 whereby the air inlet openings are closed with substantially the full volume of air from fans 40 and 41 passing through the housing 14 to the upper air outlet openings.

Note that the mounting holes in openings 32, 33, 34 are identical and will therefore accommodate either fans or shutters. This provides a means for obtaining additional forced air cooling by substituting fans for shutters as desired.

Although I have described my novel invention with respect to its preferred embodiments, it should be understood that many modifications and variations thereof will now be obvious to those skilled in the art, and I prefer therefore to be limited not by the specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A cooling system for an enclosed housing; said housing having a support plate adjacent a bottom wall thereof; a plurality of gas inlet openings in said support plate; a plurality of gas outlet openings in the upper portion of said housing; fan means mounted in one of said gas inlet openings for moving gas through said inlet openings and through said enclosed housing and out of said outlet openings, and shutter means mounted in the other of said gas inlet openings; a respective pivotal support means connected to said support plate for each of said shutter means; each of said shutter means being rotatable between an open and closed position with respect to their said respective gas inlet openings; respective mechanical biasing means connected to each of said shutter means for biasing each of said shutter means to a normally open position to permit flow of gas through their said respective gas inlet openings and through said housing; each of said shutter means being moved to their said closed position against the force of their said respective mechanical biasing means responsive to the build-up of gas pressure within said housing when said fan means operates.

Z. The device substantially as set forth in claim 1 wherein one side of each of said shutters has a weight secured thereto for pivotally biasing said shutter toward its said open position.

3. The device substantially as set forth in claim 1 wherein said pivotal mounting means is connected to each of said shutters along a straight line extending across the surface of said shutters and spaced from the center of said shutters to define a relatively large area portion and an adjacent relatively low area portion on opposite sides of said line.

4. The device substantially as set forth in claim 1 wherein said bias comprises respective weights connected to said relatively small area portions of said shutters.

References Cited by the Examiner UNITED STATES PATENTS 1,508,813 9/24 Miles 9839 X 1,598,299 8/26 Miles 98-39 X 2,192,009 2/40 Jordan 98-119 2,927,736 3/60 Rohatyn 9833 ROBERT A. OLEARY, Primary Examiner. 

1. A COOLING SYSTEM FOR AN ENCLOSED HOUSING; SAID HOUSING HAVING A SUPPORT PLATE ADACENT A BOTTOM WALL THEREOF, A PLURALITY OF GAS INLET OPENINGS IN SAID SUPPORT PLATE, A PLURALITY OF GAS OUTLET OPENINGS IN TE UPPER PORTION OF SAID HOUSING; FAN MEANS MOUNTED IN ONE OF SAID GAS INLET OPENINGS FOR MOVING GAS THROUGH SAID INLET OPENINGS AND THROUGH SAID ENCLOSED HOUSING AND OUT OF SAID OUTLET OPENINGS, AND SHUTTER MEANS MOUNTED IN THE OTHER OF SAID GAS INLET OPENINGS; A RESPECTIVE PIVOTAL SUPPORT MEANS CONNECTED TO SAID SUPPORT PLATE FOR EACH OF SAID SHUTTER MEANS; EAC OF SIAD SHUTTER MEANS BEING ROTATABLE BETWEEN AN OPEN AND CLOSED POSITION WITH RESPECT TO TEIR SAID RESPECTIVE GAS INLET OPENINGS; RESPECTIVE MECHANICAL BIASING MEANS CONNECTED TO EACH OF SAID SHUTTER MEANS FOR BIASING EACH OF SAID SHUTTER MEANS TO A NORMALLY OPEN POSITION TO PERMIT FLOW OF GAS THROUGH THEIR SAID RESPECTIVE GAS INLET OPENINGS AND THROUGH SAID HOUSING; EACH OF SAID SHUTTER MEANS BEING MOVED TO THEIR SAID CLOSED POSITION AGAINST THE FORCE OF THEIR SAID RESPECTIVE MECHANICAL BIASING MEANS RESPONSIVE TO THE BUILD-UP OF GAS PRESSURE WITHIN SAID HOUSING WHEN SAID FAN MEANS OPERATES. 